Step switching mechanism switchable forward and backward

ABSTRACT

A step switch mechanism operable in both forward and reverse directions has a common feeler for both directions. The feeler is tiltable toward the desired direction and simultaneously slidable transversely to the direct of operation.

United States Patent [1 1 [111 3,876,848

Hartmann 1 Apr. 8, 1975 1 STEP SWITCHING MECHANISM SWITCHABLE FORWARDAND BACKWARD Inventor: Fritz Hartmann, 1m Heuschlag 9,

852 Erlangen, Germany Filed: Jan. 31, 1974 Appl. No.: 438,470

References Cited UNITED STATES PATENTS 4/1972 Jordan et a1. 200/156FOREIGN PATENTS OR APPLICATIONS 1,110,276 7/1961 Germany 200/156 PrimaryExaminer-Robert K. Schaefer Assistant Examiner-William J. SmithAttorney, Agent, or Firm-Robert H. Jacob [57] ABSTRACT A step switchmechanism operable in both forward and reverse directions has a commonfeeler for both directions. The feeler is tiltable toward the desireddirection and simultaneously slidable transversely to the direct ofoperation.

6 Claims, 4 Drawing Figures STEP SWITCHING MECHANISM SWITCHABLE FORWARDAND BACKWARD The invention concerns a step switching mechanism that canbe operated in forward and reverse directions. It already has beenproposed in connection with such a step switching mechanism to provide acommon feeler for both directions of movement which, depending on thedesired direction of operation, is tiltable to ward the desireddirection of operation of its position of rest in one direction or theother and simultaneously slidable transversely to the direction ofoperation. In this connection the feeler acts on operating steppingmeans of a driven part in the existing direction of operation and istiltable to both sides in a sliding guide and displaceably supportedobliquely to the direction of operation. A spring supported against thehousing counteracts its displacement in the longitudinal direction inthe guide.

Step switching mechanisms of this type can serve in connection withswitches and leads as coding switches, for example for decimal or binarycode systems.

In the proposed step switching mechanism the further switching of thedriven part takes place in two distinctly separated half steps. Theactuating feeler path has a break, so that there is danger that theoperator may release the feeler button after a half step, which canresult in faulty switching.

The invention is based on the problem of equipping a step switchingmechanism of the proposed type in such a manner that a short sensingpath is provided owing to which the measure of division can be selectedto be very small, and rapid setting is made possible and the sensingpath extends continuously.

In accordance with the invention this problem is solved in the forwardand backward switchable step switching mechanism described above in thatthe sensor is constructed in one piece with a feeder button for eachdirection of movement of the connection of the scanning buttons has asmall resilient bridge, that two stationary abutment studs are provided,one of each of which cooperates with a coordinated oblique edge of thefeeler, and that the feeler has two transport studs symmetrical with thelongitudinal axis and a transport wedge in the longitudinal axis whichcooperate with a star-shaped sprocket wheel of the driven part.

By means of the invention a step switching mechanism is provided whichconsists essentially of merely three parts, which can be set rapidly andeasily without danger of faulty switching.

It is particularly suitable when the transport wedge is constructed asborder limit of the guiding slide.

In the preferred embodiment of the invention the guiding slide consistsof a longitudinal slot having oblique sliding surfaces in the feeler anda securing stud fixed on the housing.

Advantageously the transport studs are each provided with a cutter-likeedge whose flanks are facing one another and are longer than the outerflanks.

In a preferred embodiment of the invention the FIG. 1, a longitudinalsection through a step switching mechanism in accordance with theinvention,

FIG. 2, a plan view of an opened step switching mechanism,

FIG. 3, a digit wheel as a driven part, and

FIG. 4, a feeler as driving part.

In a housing 1 having a window cutout 1a, a fixed axis lb for a digitwheel 2 is provided with a suitable bore. Furthermore a right abutmentstud 1d is in the bottom of the housing 1, and a left abutment stud 1eas well as a rearward fixing stud 1c are formed. The housing furthermorehas a right cutout 1f in its forward wall for a feeler and a left cutout1g for a second feeler.

In the embodiment illustrated a digit wheel 2 serves as driven part witha wheel mantle 2a and a star-shaped sprocket wheel 2b serving asswitching or advancing member. A free space 20 is provided for a contactdevice.

In the housing 1 a sensor 3 is longitudinally slidable and disposedsomewhat tiltably in two directions. The feeler 3 has two limiting ribs31' for a pressure spring 4 which supports itself against the rear wallof the housing 1 and counteracts any longitudinal displacement of thefeeler 3, so that the pressure spring 2 also applies a resetting forceafter the feeler actuation has taken place.

For each direction of movement of the driven part 2 a feeler knob isprovided, which in the drawing are illustrated as right feeler knob 3aand left feeler knob 3b. The feeler knobs 3a and 3b are made toconstitute a unitary member with the remaining feeler 3 and areconnected with the main part by way of resilient parts 32 and 32. Thenarrowing in the area of the resilient parts 3e and 3e is formed by oneeach cutout which merge into an oblique abutment or sliding surface 3/1,3/1. Abutment studs 1d and 1e fixed to the housing are associated withthese sliding surfaces 311 and 3/1. In the forward area transport studs30 and 3d are arranged on the feeler which are provided with a cuttingedge 30c or 3a'd. These cutting edges 3cc and 3dd cooperate with theteeth 2b of the star-shaped sprocket wheel 2b.

In the rearward area the feeler 3 extends through a sliding guide whichconsists of a cutout 3g for a fixing stud 10 that is secured to thehousing and an oblique sliding surface 3g. The forward limit of thecutout 3g is defined by a transport wedge 3f with a cutting edge 3f,each of which cooperates with the cutout between two teeth of thestar-shaped sprocket wheel 2.

In the position of rest the feeler 3 is disposed symmetrically inhousing 1, the feeler knobs 3a and 3b are guided in the housing cutoutslfand 1g, and in the cutout 3g extends the securing stud 1c. The digitwheel 2 is journalled by means of its central bore on the axis lbstationary in the housing. The transport wedge 3f is pressed by pressurespring 4 against the toothed crown 2b and effects a fixed angularposition of the digit wheel 2.

On pressing a feeler knob, for example 3a, a pressure is applied againstpressure spring 4 that is disposed against the direction of pressure.The feeler 3 rocks during the first phase in clockwise direction untilthe abutment and sliding surface 311 contacts the abutment stud 1d. Theresilient part 3e makes possible the rocking of the feeler 3. Thecutting edge 3cc of the transport stud 3c has been moved laterally tothe tooth point 2b. In the second phase the feeler 3 slides with itsoblique sliding surface 3h against the abutment stud 1d and with itssliding surface 3g against the fixing stud 1c in the direction of thepressure spring 4. Thus the transport wedge 3freleases the toothed crown2b, the transport stud 3c enters with its cutting edge 30c laterally ofthe tooth point 2b and turns the digit wheel 2 by onehalf toothedportion in counterclockwise direction. The oblique arrangement of thesliding surface 311 thereby effects that the toothed crown 2b comes torest with the tooth point 2b exactly on the horizontal center line,respectively the longitudinal axis. This is a prerequisite for thefurther transporting operation. Now the transport step has been halfcompleted. When the feeler knob 3a is now freed, the pressure spring 4presses the feeler 3 again into its starting position, re-

spectively its position of rest. The transport wedge 3f that is disposedlaterally of the tooth point 2b owing to the oblique arrangement of thesliding surface 3g engages in such a manner that the digit wheel isturned in counterclockwise direction until the corresponding switch restposition has been fully reached.

The left half of the feeler and of the housing are symmetricallyconstructed, so that on operating the left feeler knob 3b the digitwheel 2 is turned further in clockwise direction in an analogicalmanner.

The housing 1 may be covered in a manner known per se and not shown, andmay, if necessary, be provided with a printed circuit whereby theclosure plate has a border extending above the housing which carries theouter contacts or connections.

The digit wheel 2 has numerals or other symbols which can be seen in thewindow cutout la provided at the operating side of the housing 1.

A step switching mechanism in accordance with the invention may also beproduced with very small dimensions where the numberings on the digitwheel are relatively large. For this purpose the construction is suchthat in a known manner several step switching mechanisms are disposedalongside one another or above one another and can be connected witheach other.

Thus, the invention is not limited to the embodiment illustrated anddescribed. It encompasses also all professional modifications as well asall parts and subcombinations of the described and/or illustratedfeatures or measures.

Having now described my invention with reference to the embodimentillustrated in the drawings, what l desire to protect by letters patentof the United States is set forth in the appended claims.

I claim:

1. Forward and backward switchable step switching mechanism comprising afeeler common to both directions of operation tiltable from a positionof rest in one direction or the other and simultaneously slidabletransversely to the direction of operation, and including a driven parthaving switching means acted upon in the existing direction ofoperation, sliding guide means supporting said feeler for tiltingmovements in opposite directions and for sliding movements transverselyof the direction of operation, a spring biasing said feeler in saidhousing against longitudinal displacement, said feeler having one eachunitary knob for each direction of movement and one each resilientbridge for connecting said feeler knobs with said feeler, two stationaryabutment studs being provided, said feeler having 0blique edges, oneeach cooperating with an abutment stud and having two transport studsextending symmetrically to the longitudinal axis and having a feedingwedge disposed along the longitudinal axis proximate said driven part.

2. Step switching mechanism in accordance with claim 1 where saidfeeding wedge is the border limit of said sliding guide means.

3. Step switching mechanism in accordance with claim 2, where saidsliding guide means is defined by an elongated slot having obliquesliding surfaces on said feeler and a stationary stud.

4. Step switching mechanism in accordance with claim 1 where saidtransport studs each present an edge having opposite flanks that are nolonger than the outer flanks.

5. Step switching mechanism in accordance with claim 1 having a drivenmember defining a digit roller or the like and said housing having afixed axis encompassed by said feeler.

6. Step switching mechanism in accordance with claim 5 where allcomponents excepting the spring are made of plastic material.

l l l

1. Forward and backward switchable step switching mechanism comprising afeeler common to both directions of operation tiltable from a positionof rest in one direction or the other and simultaneously slidabletransversely to the direction of operation, and including a driven parthaving switching means acted upon in the existing direction ofoperation, sliding guide means supporting said feeler for tiltingmovements in opposite directions and for sliding movements transverselyof the direction of operation, a spring biasing said feeler in saidhousing against longitudinal displacement, said feeler having one eachunitary knob for each direction of movement and one each resilientbridge for connecting said feeler knobs with said feeler, two stationaryabutment studs being provided, said feeler having oblique edges, oneeach cooperating with an abutment stud and having two transport studsextending symmetrically to the longitudinal axis and having a feedingwedge disposed along the longitudinal axis proximate said driven part.2. Step switching mechanism in accordance with claim 1 where saidfeeding wedge is the border limit of said sliding guide means.
 3. Stepswitching mechanism in accordance with claim 2, where said sliding guidemeans is defined by an elongated slot having oblique sliding surfaces onsaid feeler and a stationary stud.
 4. Step switching mechanism inaccordance with claim 1 where said transport studs each present an edgehaving opposite flanks that are no longer than the outer flanks.
 5. Stepswitching mechanism in accordance with claim 1 having a driven memberdefining a digit roller or the like and said housing having a fixed axisencompassed by said feeler.
 6. Step switching mechanism in accordancewith claim 5 where all components excepting the spring are made ofplastic material.